CVE-2026-43203

Updated on 06 May 2026

Severity

7.5 High severity

Details

CVSS score
7.5
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H

Overview

About vulnerability

In the Linux kernel, the following vulnerability has been resolved:

atm: fore200e: fix use-after-free in tasklets during device removal

When the PCA-200E or SBA-200E adapter is being detached, the fore200e is deallocated. However, the tx_tasklet or rx_tasklet may still be running or pending, leading to use-after-free bug when the already freed fore200e is accessed again in fore200e_tx_tasklet() or fore200e_rx_tasklet().

One of the race conditions can occur as follows:

CPU 0 (cleanup) | CPU 1 (tasklet) fore200e_pca_remove_one() | fore200e_interrupt() fore200e_shutdown() | tasklet_schedule() kfree(fore200e) | fore200e_tx_tasklet() | fore200e-> // UAF

Fix this by ensuring tx_tasklet or rx_tasklet is properly canceled before the fore200e is released. Add tasklet_kill() in fore200e_shutdown() to synchronize with any pending or running tasklets. Moreover, since fore200e_reset() could prevent further interrupts or data transfers, the tasklet_kill() should be placed after fore200e_reset() to prevent the tasklet from being rescheduled in fore200e_interrupt(). Finally, it only needs to do tasklet_kill() when the fore200e state is greater than or equal to FORE200E_STATE_IRQ, since tasklets are uninitialized in earlier states. In a word, the tasklet_kill() should be placed in the FORE200E_STATE_IRQ branch within the switch…case structure.

This bug was identified through static analysis.

Details

Fixes

KernelCare state

Live-patch status from KernelCare for each operating system.

Operating system Status Covered kernels
Debian 11 Released
37 kernels
  • 5.10.46-5
  • 5.10.70-1
  • 5.10.46-4
  • 5.10.84-1
  • 5.10.92-1
  • 5.10.92-2
  • 5.10.103-1
  • 5.10.106-1
  • 5.10.113-1
  • 5.10.120-1
  • 5.10.127-1
  • 5.10.127-2
  • 5.10.136-1
  • 5.10.140-1
  • 5.10.149-1
  • 5.10.149-2
  • 5.10.158-2
  • 5.10.162-1
  • 5.10.179-1
  • 5.10.179-2
  • 5.10.179-3
  • 5.10.179-5
  • 5.10.191-1
  • 5.10.197-1
  • 5.10.178-3
  • 5.10.205-2
  • 5.10.205-1
  • 5.10.209-2
  • 5.10.216-1
  • 5.10.218-1
  • 5.10.221-1
  • 5.10.223-1
  • 5.10.226-1
  • 5.10.234-1
  • 5.10.237-1
  • 5.10.244-1
  • 5.10.247-1
Debian 11 cloud Released
17 kernels
  • 5.10.113-1
  • 5.10.179-2
  • 5.10.179-3
  • 5.10.179-5
  • 5.10.191-1
  • 5.10.197-1
  • 5.10.205-2
  • 5.10.209-2
  • 5.10.216-1
  • 5.10.218-1
  • 5.10.221-1
  • 5.10.223-1
  • 5.10.226-1
  • 5.10.234-1
  • 5.10.237-1
  • 5.10.244-1
  • 5.10.247-1
Debian 13 Planned
Ubuntu 22.04 Planned
Ubuntu 24.04 Will Not Fix
45 kernels
  • 6.8.0-35.35
  • 6.8.0-38.38
  • 6.8.0-36.36
  • 6.8.0-39.39
  • 6.8.0-40.40
  • 6.8.0-41.41
  • 6.8.0-44.44
  • 6.8.0-45.45
  • 6.8.0-31.31
  • 6.8.0-47.47
  • 6.8.0-48.48
  • 6.8.0-49.49
  • 6.8.0-50.51
  • 6.8.0-51.52
  • 6.8.0-52.53
  • 6.8.0-54.56
  • 6.8.0-55.57
  • 6.8.0-53.55
  • 6.8.0-56.58
  • 6.8.0-57.59
  • 6.8.0-58.60
  • 6.8.0-59.61
  • 6.8.0-60.63
  • 6.8.0-62.65
  • 6.8.0-63.66
  • 6.8.0-64.67
  • 6.8.0-71.71
  • 6.8.0-78.78
  • 6.8.0-79.79
  • 6.8.0-84.84
  • 6.8.0-85.85
  • 6.8.0-83.83
  • 6.8.0-86.87
  • 6.8.0-87.88
  • 6.8.0-88.89
  • 6.8.0-90.91
  • 6.8.0-94.96
  • 6.8.0-100.100
  • 6.8.0-101.101
  • 6.8.0-106.106
  • 6.8.0-107.107
  • 6.8.0-110.110
  • 6.8.0-111.111
  • 6.8.0-117.117
  • 6.8.0-124.124
Ubuntu 24.04 AWS Planned